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Huge Ocean Confirmed Underneath Solar System's Largest Moon

Posted by samzenpus on from the under-the-sea dept.

sciencehabit writes The solar system's largest moon, Ganymede, in orbit around Jupiter, harbors an underground ocean containing more water than all the oceans on Earth, according to new observations by the Hubble Space Telescope. Ganymede now joins Jupiter's Europa and two moons of Saturn, Titan and Enceladus, as moons with subsurface oceans—and good places to look for life. Ceres, the largest object in the asteroid belt, may also have a subsurface ocean. The Hubble study suggests that the ocean can be no deeper than 330 kilometers below the surface.

80 of 117 comments (clear)

  1. Life by hooiberg · · Score: 4, Insightful

    How did life start on earth? Water, with trace elements, under pressure, with a magnetic field to protect against the worst of the solar radiation.
    And what have we here? Water, with trace elements, under pressure, with a magnetic field to protect against the worst of the solar radiation.

    1. Re:Life by abies · · Score: 5, Insightful

      Except it is not a solar radiation you need protecting against (Sun is very far), but Jupiter radiation. Unfortunately despite magnetosphere, Ganymede gets around 8 rem of radiation per day (http://en.wikipedia.org/wiki/Colonization_of_the_outer_Solar_System#Ganymede), which is bit too much for life as we know it. Fortunately, it is not going to be an issue 300km below the surface - but at that depth, you don't need magnetosphere anyway.

      I think that biggest problem for life there would be availability of energy. 300km of crust is probably shielding external energy too well, so internal heat would be probably only viable source of that. Might be not enough to sustain life (or even more, to produce it randomly)

    2. Re:Life by hooiberg · · Score: 5, Insightful

      On the other hand, heat built up by tidal forcing of Jupiter will also not be able to escape easily, through such a thick crust. Remember that we have many deep-ocean creatures on earth, where there is no light, and the water is so cold that it is barely liquid. (zero to three degrees Celsius).

      Actually, it has been estimated there are so many deep-ocean species, that bioluminescence might be the most common method of communication on earth.

    3. Re:Life by itzly · · Score: 2

      And all we need to do to take a sample is a launch a probe with a 300 km long drill bit. Easy peasy.

    4. Re:Life by Anonymous Coward · · Score: 1

      Just for reference:
      The Kola Superdeep Borehole is roughly 12 km deep.

    5. Re:Life by Rei · · Score: 3, Insightful

      And you know that those are the requirements for LAWKI how? Ignoring the fact that there could be entirely different requirements for other entirely types of life elsewhere, you have no clue how the earliest forms of life on Earth began.

      If Titan's natural abiotic organic chemistry laboratory offers any clues, for example, the start of life could have come because of ionizing solar radiation, and in the absence of water, and only later developed into our present form. On Titan solar ionizing radiation builds complex organic compounds, some having been measured at over 10000 daltons, of carbon, hydrogen, and nitrogen, which raises the potential of catalytic cycles.

      There have been countless proposed mechanisms for the earliest forms of autocatalysis that could have led up to the theoretical RNA world that could have led to our present world. And orders of magnitude more not yet conceived that could potentially have done it. It's silly to pretend that we have any clue exactly what the requirements are for the earliest "ancestor" to life on Earth. We don't know whether it developed in an ocean, on land, in a lake, in the soil, in rocks deep underground, in the troposphere, in the exosphere, in space... we really don't know. We don't know where it developed and we don't know what it was, and we don't know if it was the only way life could form (but I'd wager "no").

      --
      "Are you hungry? I haven't eaten since later this afternoon." -- Primer
    6. Re:Life by Rei · · Score: 5, Interesting

      I should add that we need to think better about how we want to think about early life, what's likely to lead to an evolutionary path.

      On one hand, we have self replicators like the misfolded prions of BSE. Injected into a healthy human, a single misfolded prion can begin taking others in the person's body and misfolding them, leading to a catalytic cycle that spreads like a virus and eventually kills the person. One could conveive that if there were a wide range of "roughly prion-like" chemicals in some primordial soup, that their variations in folding could lead to evolutionary adaptation with time.

      Is this reproduction some realistic sort of form of protolife? By far most people would say no. Prions are large, complex proteins; the concept of an early world containing large amounts of this exceedingly specific complex protein, or even proteins not exactly the same but still similar enough for reproduction, is exceedingly unlikely.

      On the other hand, let's look at something like tin pest. Objects made of pure tin are stable at warmer temperatures, but at low temperatures they can develop something called "tin pest" where tiny spots break out, and then over the course of months expand and eat up the object, breaking it down into dust, like bacterial colonies spreading across a petri dish. This is a low-temperature stable allotrope of tin which catalyzes its own formation to reproduce itself.

      Is this reproduction some realistic soft of form of protolife? By far, most people would say no. Contrary to prions, it's input is quite simple: plain, ordinary tin. It's easy to picture where this specific case or other natural cases like it could occur in some early world. But its problem is different: it's too specific. Tin pest seems unlikely to, say, mutate and start catalyzing the production of phospholipids or similar. It's just one self-catalytic reaction, with no real possibility for alterations.

      The earliest forms of protolife surely lie somewhere on the spectrum in-between these two endpoints - not with such glaringly simple inputs as tin pest, such that your reaction is too simple to have any chance of it mutating without outright dying off, but not with inputs so complex as prions that you're unlikely to ever find significant quantities in nature. Surely the earliest forms were some sort of middle ground.

      But what they were, specifically? This is totally and utterly unknown at this time.

      --
      "Are you hungry? I haven't eaten since later this afternoon." -- Primer
    7. Re:Life by PhilHibbs · · Score: 1

      330km is the upper bound for depth, but the real question is, what's the lower bound? I want to see error bars!

    8. Re:Life by Anonymous Coward · · Score: 1

      330km from the other side.

    9. Re: Life by Anonymous Coward · · Score: 1

      Wow this is the most insightful comment on slashdot in eons

    10. Re:Life by TapeCutter · · Score: 5, Interesting

      The four Galilean moons are interesting from an evolutionary POV.
      Io - Molten sulphur on the surface, purple volcanoes all over it.
      Europa - Deep water ocean, thin crust, very active plate tectonics.
      Ganymede - Europa with a deep dish crust and cooler core.
      Callisto - A rock.

      So it would seem that gas giants may have their own "goldilocks zone" when they are orbiting in the colder regions of their host system. So the "average" solar system may have 3-4 "habitable zones" rather than just one.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    11. Re:Life by Anonymous Coward · · Score: 4, Insightful

      On the other hand, heat built up by tidal forcing of Jupiter will also not be able to escape easily, through such a thick crust.

      Heat "build-up" is not enough, you need a heat gradient with some sort of heat flow. Life and chemistry doesn't bypass thermodynamics. If the water and ground below it is very even, with the gradient in solid material above, there might not be enough of an energy source to allow life to form.

    12. Re:Life by s_p_oneil · · Score: 2

      Or if the surface is ice, with enough energy to melt through 300km of it. It still might need a 300km long antenna to tell us if it finds anything. I doubt a signal would go through 300km of solid ice very well.

    13. Re:Life by dissy · · Score: 2

      But let us reword your position for a moment to point out the folly (currently at least) in its usefulness.

      Here in my home country, if I desired a hamburger I happen to know from experience that most restaurants will have such a thing to sell to me. Ignoring jokes about McDonalds not having real food for just a moment, I know they are the most common place around to find a hamburger at.

      Then you come along and (correctly, but uselessly) point out that the laws of physics do not rule out the possibility of finding a hamburger sitting around in some random persons back yard, and so such places should all be equally searched as well.

      Yet if you or I were to travel to a country we have never been to before and happened to desire a hamburger, we would search out a restaurant knowing the chance of finding a hamburger there, even without ever having visited a restaurant in that country before.

      No one is actually arguing that it wouldn't be possible to find a hamburger in a random persons backyard (although many would argue if it would be a good idea to eat it :P ) but from experience we know the odds of finding one in such a place are much much lower than compared to a restaurant.

      Likewise, we know life on earth is more likely to be found in water than not.
      That doesn't mean there is NO life outside of the water at all, just that the odds of finding it in water are higher than finding it elsewhere.

      Again, no one is actually arguing that water is required for life in general, only that our sample of one shows a much higher chance of finding it, and our sample size of one is all we have to formulate characteristics to actually look for and detect.

      So looking for life in water, that is similar to life on earth, is what we have the best description of (as crappy as it may be) and so the best chance of actually detecting, and our one sample shows it as the highest likelihood of occurring in water.

      This is why we look for water and use the characteristics of life we have to match on - because it gives the best chance of success.

      As our samples of majorly differing life forms increases and our characteristics to match on increase, we will have better odds of success looking elsewhere.

      But with our current knowledge and technical level, it makes no sense to search for hamburgers in random back yards when we can search in restaurants first.

      You always aim for the low hanging fruit first, then move on to the harder to reach fruit after.
      You have to learn to walk before you can run.
      Insert additional cheesy proverbs here (especially if they make good hamburger toppings! sorry, I think I'm hungry)

      Just because searching for life as we know it in water is the first step does not exclude all the other harder to detect steps, it only delays them until later, hopefully to a time we are better equipped to do so both with technology and our knowledge.

      It's also worth pointing out that no one is actually forcing you to look in the most common places for the things we know how to detect - you are free to look anywhere you like for things you can't describe, if you so wish.
      It's just that your odds of success are so drastically lower, even compared to the already seemingly low chances in finding life in water on another world, that few people would be willing to throw money at you for the task.

      And that, put simply, is why we look for water on other worlds in our search for life.

    14. Re:Life by hooiberg · · Score: 1

      As more and more extremophiles are found (bacteria living on radiation, on pure oil, on sulphur, you name it...) the number of habitable zones will grow. However, whether those zones will be able to support life that will eventually develop into a space faring civilisation... I am not so sure.

    15. Re:Life by Applehu+Akbar · · Score: 1

      Tin pest fails the irritability life criterion, though: if you poke it, it does not respond. Do prions?

    16. Re:Life by gatkinso · · Score: 1

      Would the borer have to be attached? It could trail a fiber optic cable.

      But yeah, this is a bit "tricky" at best.

      --
      I am very small, utmostly microscopic.
    17. Re:Life by MachineShedFred · · Score: 2

      it could leave a repeater at the top of the shaft before it starts boring in. It sends a low power signal to that, which then boosts it with a high-gain directional which stays pointed at Earth, or even a satellite with another repeater.

      Yes, that's all very heavy, but so is 300km of cable

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
    18. Re:Life by ShanghaiBill · · Score: 1

      However, whether those zones will be able to support life that will eventually develop into a space faring civilisation... I am not so sure.

      A big barrier to that is the number of extinction events. The gravity from a gas giant pulls in a lot of passing comets and asteroids, that are quite likely to smack into the moons as they fall in. EEs would be ten to a hundred times more common for a gas giant moon than for a planet like Earth. The 1994 Jupiter impact would have likely wiped out any complex life if it hit a moon the size of Ganymede.

    19. Re:Life by Falos · · Score: 1

      Not yet. In my dictionary, protolife (read, pre-life) is self-replicating assemblies, including prions but also tin pest and even fire. Any construct that has that seemingly self-preserving reproduction, which inadvertently causes population and sustained presence, the scoreboard of something well-evolved and adapted.

      However, only protolife with variance can evolve. I'm not sure it's exhaustively impossible to see tin pest change: Consider some kind of unusual variant or alloy that is less susceptible to being eroded by water, and more importantly, populates as much and as often and either it reaches nearby environments or it is a "mutation" of some noticeable frequency. Some, most, or all tin pest would be of this variety. And yet ultimately, like GP said, this lacks real mutation, the chain of possibilities isn't there. It only coincides with sustained presence.

      GP's prion is some kind of brown goo scenario, but it seems like it leans on an abundance of inert proteins, or protobiosphere. I still lean towards this endpoint because of increased variant options over tin by sheer chemistry, because "more stable" variants will probably be (inadvertently) leveraging properties that are more True Scotsman "life", like incidental locomotion. Or maybe they clump. Or, hell, I don't know, because disclaimer: I'm speculating out my ass and don't know shit about the subject.

    20. Re:Life by MightyMartian · · Score: 2, Informative

      Keep in mind that there is virtually no evidence for panspermia.

      --
      The world's burning. Moped Jesus spotted on I50. Details at 11.
    21. Re:Life by mrchaotica · · Score: 2

      Some of them do. The ones that don't, however, rely (as far as we know) on 'marine snow', which would not exist on Ganymede.

      --

      "[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz

    22. Re:Life by binarstu · · Score: 1

      Actually, it has been estimated there are so many deep-ocean species, that bioluminescence might be the most common method of communication on earth.

      I'm curious if you have a source for that estimate (because I actually would like to read more).

    23. Re:Life by itzly · · Score: 1

      Since we have no way to actually take a sample of the water on Ganymede, it's all just speculation anyway. And if we're just speculating, there's no point in restricting ourselves to Earth-like circumstances.

    24. Re:Life by towermac · · Score: 1

      They mean that the depth of the liquid ocean is up to 330km deep; not that the crust is that thick above the liquid. As far as I know, thickness of the crust is at this point speculation. It has to have some substantial thickness; if it were very thin, we would expect to see lots of infrared escaping.

      But it is not necessarily impenetrably thick. There could be things like atmospheric replenishment in Jupiter's general vicinity. Where the very cold atmospheric trail left behind removes heat from the frozen surface, leaving us with a cool infrared signature, and a crust far thinner than it would appear. That would be very hard to spot with the Hubble.

    25. Re:Life by skastrik · · Score: 2

      The four Galilean moons are interesting from an evolutionary POV. Io - Molten sulphur on the surface, purple volcanoes all over it. Europa - Deep water ocean, thin crust, very active plate tectonics. Ganymede - Europa with a deep dish crust and cooler core. Callisto - A rock.

      Yes, I imagine the birds will have quite different types of beaks.

    26. Re:Life by ColdWetDog · · Score: 1

      Life is obviously exceedingly adaptable; extremophiles in all kinds of crazy conditions have been discovered. But I don't think anyone suggests that life actually arose in such extreme conditions. You need somewhere more favorable for living organisms to come from, then produce extremophile descendants.

      Not necessarily. You might need more time to produce viable life forms under less than ideal circumstances, but if you can support life at all, conditions could have created the life form in the first place. Of course, this is the big question - what parameters are really needed for life to form. Since we are at n=1, we need more data....

      --
      Faster! Faster! Faster would be better!
    27. Re:Life by plopez · · Score: 1

      You missed short wave radiation. Earth has it, Ganymede does not. That could just any hope of finding life.

      --
      putting the 'B' in LGBTQ+
    28. Re:Life by ColdWetDog · · Score: 1

      Really what you describe is the RNA world hypothesis (which you actually mention) - only you substitute some other polymer for RNA.

      Breaking this down to first principles, you basically need conditions where ** something ** forms a semi stable polymer and those conditions are stable enough for random chance to allow autocatalysis. That something probably can't be just a metal but isn't necessarily carbon-hydrogen. So there are lots of potential environments for life to occur. How often this actually happens is, of course, subject to much debate.

      But given the enormous number of potential types of chemistries, the enormous numbers of different environments and one hell of a lot of time for the molecules to muck about, it seems that life has to have evolved in more than one place and more than one time.

      --
      Faster! Faster! Faster would be better!
    29. Re:Life by hairyfeet · · Score: 1, Interesting

      I would say its EXTREMELY unlikely to support intelligent life and here is why....complex brains require a LOT of energy and if you remove the marine snow (which would be almost impossible because as others pointed out the upper parts of the ocean would be getting high levels of radiation) from the bottom of the ocean? Its extremely energy poor.

      Remember for evolution one has to have the energy capable of supporting that new form and we have plenty of evidence in the record of evolutionary "dead ends" because the environment would no longer sustain them, see the dinosaurs. With only a poor energy source its doubtful they would be able to evolve anything more complex than worms but that doesn't mean we shouldn't go explore simply because finding such a creature would answer many questions about how life began here, such as whether DNA is the only way and whether its always going to be right handed.

      --
      ACs don't waste your time replying, your posts are never seen by me.
    30. Re:Life by OutOnARock · · Score: 1

      Repo Man (the movie):

      J. Frank Parnell

      Ra-di-a-tion. Yes, indeed. You hear the most outrageous lies about it. Half-baked goggle-box do-gooders telling everybody it's bad for you. Pernicious nonsense! Everybody could stand a hundred chest X-rays a year! They oughta have 'em, too.

    31. Re:Life by MachineShedFred · · Score: 1

      Under extremely low atmospheric pressure, it's likely the water would not stay water - it would sublimate to vapor. Nobody said it would be easy and wouldn't present challenges.

      --
      Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
  2. Finally! by Pikoro · · Score: 5, Funny

    Finally a reason to kick-start manned space exploration! Think of what can be learned! If there is life on these moons, then that means that it will also die. Dead plants means ocean floor sediment. That means there could be oil there! We now have a reason!

    --
    "Freedom in the USA is not the ability to do what you want. It is the ability to stop others from doing what THEY want"
    1. Re:Finally! by jbmartin6 · · Score: 1

      Or perhaps the corpses of these monkeys in a can would seed the moon with life, panspermia ex machina.

      --
      This posting is provided 'AS IS' without warranty of any kind, implied or otherwise.
    2. Re:Finally! by delt0r · · Score: 1

      Why does it need to be manned? probes and stuff without meat bags that need metric tons of life support would give far better return.

      --
      If information wants to be free, why does my internet connection cost so much?
    3. Re:Finally! by R3d+M3rcury · · Score: 1

      Maybe if we put down a giant monolith...

  3. Rocket Fuel by Dollyknot · · Score: 1

    What has not been realised is, that water is actually rocket fuel, split it into oxygen and hydrogen. And Bob's your uncle.

    Regards Peter.

    --
    It's called an elephant's trunk whereas it is in fact, an elephant's nose, a nose by any other name would smell as sweet
  4. Farmer in the sky by uksv29 · · Score: 1

    This story brings back memories of when I was a kid and read the book "Farmer in the sky" by Robert A. Heinlein. I really wanted to be there on Ganymede.

    Maybe this increases the chances of us going there in the future provided we haven't bioengineered ourselves into extinction..

    1. Re:Farmer in the sky by Guy+From+V · · Score: 1

      I propose the next probe or mission to Ganymede be called Torchship 1.

  5. Re:That can't be right... by Anonymous Coward · · Score: 2, Insightful

    because the Greens tell us that we'll soon have used up all the water on the Earth,

    When you slap labels on your "enemies" and then ascribe to them absurd positions you're doing yourself a disservice. You stop thinking rationally and dismiss any notion that doesn't already fit with your ideas.

  6. Molten Ice by Alsee · · Score: 1

    If this magma reaches the surface it could result in lava flows.

    -

    --
    - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
  7. Re:That can't be right... by Thanshin · · Score: 4, Funny

    I'm pretty sure that's going to be the most stupid thing I read all day. ...

    Ok. I HOPE, that's the stupidest, but I have a budget meeting in less than an hour, so I'm not really that confident.

  8. Re:That can't be right... by tehcyder · · Score: 1

    ...containing more water than all the oceans on Earth ... ...because the Greens tell us that we'll soon have used up all the water on the Earth, and then there'll be no more and humanity will die out. SURELY there can't be resources elsewhere?

    Not a "Green" idea I've ever heard before, but even if was genuine, I really don't think that finding water 300km below the surface of a moon round Jupiter is going to be much of a solution except possibly in the very long term.

    --
    To have a right to do a thing is not at all the same as to be right in doing it
  9. Awesome! by mjgday · · Score: 1

    Now there's a chance we can have Ganymedian dolphin pilots for our star cruisers!!!

    --
    foo
    1. Re:Awesome! by Anonymous Coward · · Score: 1

      Not unless you want to go from star system to star system in graceful leaping arcs, chasing every errant beach ball you run across.

    2. Re:Awesome! by skoaldipper · · Score: 1

      ...or get your star cruiser stuck behind a floating piece of Star Cola plastic carrying rings

      --
      I hope, when they die, cartoon characters have to answer for their sins.
  10. Re:So an ocean so deep that... by Rei · · Score: 4, Interesting

    Realistically, it's hard to picture any method that would work other than a nuclear reactor melting itself down through the surface. But then you've got the question of how to handle communications back to the top. That's a *lot* of ice to transmit through.

    A 330km cable frozen into the ice that reforms above would be very heavy (tens of thousands of tonnes even if very lightweight), complex to feed, and probably have an unacceptable risk of breakage from shifting / settling ice.

    I guess if you considered extremely low bandwidth acceptable you could use a neutrino pulse based transmission method straight from the probe.

    Perhaps instead of 330km of cable you could drop behind hundreds of RTG-powered SLF radio repeaters (or thousands of ULF repeaters, or tens of thousands of VLF repeaters...). That'd still be of course incredibly heavy (not just for the power and radio equipment, but for the very sizeable antennae), but that'd likely be more workable than a single 330km cable.

    I guess the last option that comes to mind would be to use exceedingly low frequency RF to try to go straight through the ice from the probe itself, less than 1Hz. But surely we're talking an antenna spread out over hundreds of square kilometers to be able to do that.

    --
    "Are you hungry? I haven't eaten since later this afternoon." -- Primer
  11. Looking for life? by wjcofkc · · Score: 1

    That's great but how about sustaining human life? These could be great jumping off places for solar system colonization.

    --
    Brought to you by Carl's Junior.
    1. Re:Looking for life? by itzly · · Score: 1

      Where are you planning to jump, if a Jupiter moon is a good "jumping off place" ?

    2. Re:Looking for life? by wjcofkc · · Score: 1

      I was thinking more like intersolar trade. Water goes on giant ships to the moon every so often, and helium-three comes back. If it turns out to be to impractical to colonize distant worlds for a very long time, we must assume the colonization of the solar system works out barring we don't set ourselves back or completely annihilate ourselves, this could start to take shape in a century or so. Different places in the solar system have different resources, ships sharing resources would need to be in constant transit.

      --
      Brought to you by Carl's Junior.
  12. Re:Slow Down by Chrisq · · Score: 1

    So, we're supposed to get excited because it has water? It has virtually no atmosphere. And from Wikipedia, the temperature never gets above 152K (that's -186F). Which of those two factors is going to allow for the evolution of any life form?

    That's the surface temperature, liquid water oceans must be a lot hotter. Wikipedia estimates the core temperature as 1500–1700 K so there is certainly heat coming up.

  13. Re:320km? by uksv29 · · Score: 1

    Most of the world apart from the 5% who live in North America uses metric. Even the UK uses both Imperial and metric (although road signs are still in miles). In any case scientists and engineers all use units generally based on SI.

    Slashdot has an international readership so metric is the right choice.

  14. Re:320km? by drinkypoo · · Score: 1

    Slashdot has an international readership so metric is the right choice.

    It shouldn't really matter, because by now we should all be used to the conversions, and capable of finding a conversion calculator for use when drunk

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  15. Re:Slow Down by Alioth · · Score: 1

    That's surface temperature. This ocean is deep under the surface.

    So the follow-up question would be: if it's deep under the surface, how will sunlight get there?

    The answer is that sunlight isn't what's needed, it's the right amount of energy that's needed. The energy can come from a lot of other places. Tidal forces for example can heat the interior of the moon, radioactive decay can heat the core of a moon etc. so there may be quite a bit of subsurface energy. For example, if you look at the bottom of the oceans on Earth where there is no sunlight, there are oases of life around volcanic vents on the ocean floor (which are spewing all kinds of useful chemicals into the environment). So while the surface might be cold and lifeless, it's possible that there are significant amounts of subsurface liquid water at a temperature that's compatible with life of some description.

    --
    Oolite: Elite-like game. For Mac, Linux and Windows
  16. Re:That can't be right... by Anonymous Coward · · Score: 1

    Noticing what others say doesn't mean you actually paid attention, understood it, and are not replacing what they said with equivocation and strawmen.

    By the way, it isn't just the "Greens" but also sailors lost at sea that talk about running out of water, which must be batshit crazy in your twisted view of things considering they are in a boat surrounded by water.

  17. Re:So an ocean so deep that... by Rei · · Score: 2

    Hmm, it just occurred to me, yet one more possibility, and probably the most realistic: Fully autonomous probe. No through-the-ice communication. Contains ballast tanks. Heavier than ice when the ballast tanks are full, lighter than ice when they're empty. Mission: probe melts its way down, explores, flushes its ballast tanks with compressed air so that it's buoyant, then melts its way back to the surface. *Then* it can transmit everything that it discovered.

    --
    "Are you hungry? I haven't eaten since later this afternoon." -- Primer
  18. Re:So an ocean so deep that... by Muad'Dave · · Score: 2

    ... SLF radio repeaters ...

    Why try to brute force RF down at the DC level? Why not head to the other end of the spectrum and use lasers? If that water is relatively pure and there are few bubbles in the ice, I think lasers would win the size/weight to comm distance race.

    BTW I love the idea of a modulated neutrino beam, except how much mass would it take to even modulate it enough to be detected?

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
  19. Re:So an ocean so deep that... by Applehu+Akbar · · Score: 1

    To see what our expertise in fossil fuel exploration has accomplished in this area, visit the Nevada Test Site: long straight drilled holes 8 and 12 feet in diameter. Nothing approaching 330m\km, though.

  20. Re:Title by Applehu+Akbar · · Score: 1

    Yes it is, because Ganymede is fully differentiated geologically, with an iron core and a magnetic field.

  21. Kola Superdeep Borehole by DarthVain · · Score: 2

    Considering the deepest we've been able to bore a hole on earth with all the resources available (like air, gravity, equipment, people, etc...) was just over 12.2km deep they have a way to go...

    http://en.wikipedia.org/wiki/K...

    I was trying to come up with an analogy of something impossibly far away, more so than boring a 330km hole, on a frozen moon, on another planet, and failed.

    1. Re:Kola Superdeep Borehole by danbert8 · · Score: 1

      Admittedly though, the limits on depth of boreholes on Earth have been due to excessive heat at depth. That wouldn't be an issue drilling through ice.

      --
      Yes it's an anecdote! Were you expecting original research in a Slashdot comment?
    2. Re:Kola Superdeep Borehole by DarthVain · · Score: 1

      True. However our collective experience equals 3.7% of that value...

      Also I suspect that drilling through ice may have it's own challenges, particularly when highly tectonicly active.

      Never mind just trying to transport 330km of drill there...

  22. Oh Goodie by JimSadler · · Score: 1

    Now all we need to do is drill a hole 170 miles deep and line it with very strong pipe and we can suck that ocean to the surface to study it and see if life exists there. The weight of the drilling rig and the pipe required as well as the supporting gear might be a teeny tiny little issue and we can surely build a rocket capable of lifting all that mass into orbit. Or we could just color this picture as too expensive to ever do much with at all.

    1. Re:Oh Goodie by PPH · · Score: 1

      Now all we need to do is drill a hole

      Simpler than that. Identify a fissure in the ice covering. Collect samples from the ice and look for biological material that might have been squeezed out at the time it opened.

      --
      Have gnu, will travel.
  23. Re:So an ocean so deep that... by Rei · · Score: 1

    Lasers wouldn't even come close to working, unfortuately. Ignoring that the fact that this isn't going to be pure, bubble-free, single crystal ice - celestial bodies just don't work like that - even if it was the laser light would still attenuate way too fast. And it's even worse outside the visible spectrum.

    --
    "Are you hungry? I haven't eaten since later this afternoon." -- Primer
  24. Re:So an ocean so deep that... by Muad'Dave · · Score: 1

    I know the US Navy has performed experiments using lasers for submarine-to-surface comms - no idea on how well that went.

    How much does a 300km spool of fiber optic cable weigh again? :-)

    I wonder if sound would provide a very low bandwidth channel? If you can get good coupling into the ice ot should transmit sound relatively well.

    --
    Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
  25. ... now that's something to "mine" ... by ninjagin · · Score: 1

    Seems to me that mining the moon is a fools errand. Being able to "mine" water away from earth might be very handy -- presuming you could send it hither and yon from there.

    --
    .. pa-ra-bo-la, pa-ra-bo-la, 2 pi R, 2 pi R, where's your latus rectum, where's your latus rectum, 2 pi R
    1. Re:... now that's something to "mine" ... by itzly · · Score: 1

      Hither and yon from there is nothing but a cold hard vacuum, as far as the eye cannot see. Whatever your plans are, it's not worth it.

  26. Re:So an ocean so deep that... by itzly · · Score: 1

    Would it help if you mounted the lasers on sharks ?

  27. Re:So an ocean so deep that... by plopez · · Score: 1

    Earth First! We'll rape the other planets later...

    --
    putting the 'B' in LGBTQ+
  28. And in other news by plopez · · Score: 1

    Huge oceans confirmed on the surface of Earth, larger than any others know in the solar system. One commentator stated, "While interesting it just isn't practical to explore or colonize these oceans. We would be better off spending trillions of USD to cross 628,300,000 km to explore and colonize a far off moon. In fact we would be better off spending that money instead developing hyper drive in vain hope we are not alone in this universe."

    --
    putting the 'B' in LGBTQ+
  29. Re:So an ocean so deep that... by ColdWetDog · · Score: 1

    How about if we start by just landing on the damned moon and beaming back pictures? Maybe a Curiosity level probe, but leave the big drills until later. Who knows, maybe the Ganyamedians will come visiting (yes, the reference is to Europa, but the idea is the same).

    --
    Faster! Faster! Faster would be better!
  30. Re:So an ocean so deep that... by Dorianny · · Score: 1

    Just a crazy thought but how about a ballast tank that would make it buoyant so it could melt its way out of the ice. Ice would melt from the top, flow underneath the craft and the buoyancy would make it rise and keep melting from the top.

  31. Actually... by sycodon · · Score: 1

    ...These kinds of finds are just fueling stations for future inter-planetary ships.

    --
    When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
  32. I could have told you that by Anonymous Coward · · Score: 1

    If I stand on a boat in the middle of the Atlantic, I can look up in the direction of Ganymede and then I can look down at the ocean. Therefore, there is clearly a huge ocean underneath Ganymede.

  33. Re:So an ocean so deep that... by kenai_alpenglow · · Score: 1

    Greenpeace et. al. has a fit if you use a sonar in this ocean. They'd probably go ape-dung if you tried this on a pristine ocean....

  34. Re:So an ocean so deep that... by kenai_alpenglow · · Score: 1

    how much energy would you need to melt the ice? How dense a power supply would you need? Not trolling, just curious--and too lazy to work up the equations.

  35. Re:That can't be right... by Applehu+Akbar · · Score: 1

    You think Greens would actually support desalination? Look at these:

    http://www.foodandwaterwatch.o...
    (Huntington Beach is a small coastal town in our country which is suffering a record drought).
    http://www.citizen.org/documen...
    http://desalalternatives.org/
    http://www.dcbureau.org/201103...
    http://www.watereducation.org/...

    These links are not about random ranters, but well-funded activist groups with the legal resources it takes to tie up vital projects for as long as it takes to starve them to death. It's time we investigated where all the activist cash is coming from.

  36. Re:So an ocean so deep that... by Rei · · Score: 1

    You got me thinking. Before I'd initially dismissed sound as you'd need strong earthquake-level power outputs to be detectable on the surface. But perhaps sound repeaters might be more realistic than extremely low frequency RF repeaters? Hmm.

    Still, I think the best bet is probably just make it fully autonomous with ballast tanks and just have it surface. Ideally with enough fuel to do multiple up/down burrows, so that the first one can be a "safe" run - just down into the ocean, get as much science data (and possibly samples to take back) as you can in a short period of time, then straight back to the top to transmit it. Then once all of the basic data is sent, you could go back down and engage in riskier activities like long-distance navigation, deep dives, etc.

    --
    "Are you hungry? I haven't eaten since later this afternoon." -- Primer
  37. Utter bullshit by nessman · · Score: 1

    How many millions of dollars of taxpayer money went to 'prove' an ocean exists up to 330km beneath the moon of a planet 365 million miles away. What use is this to us... other than for a bunch of scientists to continue justifying their budget? Bah!